Railway traffic controlling apparatus



3 Sheets-Sheet l H. s. YOUNG ET AL Filed Dec. 14, 1935 RAILWAY TRAFFIC CONTROLLI NG APPARATUS 3: 3 m .NQ LMANQ QRNNEN MNNNN April 20, 1937.

INVENTORS Henry SCI bung and R0naldA.M Ca1;-n.

D THEIR ATTORNEY April 20, 1937. H. s. YOUNG ET AL 2,077,317

RAILWAY TRAFFIC CONTROLLING APPARATUS Filed Dec. 14, 1955 3 Sheets-Sheet 2 April 20, 1937. 7 H. s. YOUNG ET AL RAILWAY TRAFFIQ CONTROLLING APPARATUS 3 Sheets-Sheet 3 7 am. NW 5 a; W q @f SE m T mm my Zm J mwu 3 i MMflm {J 3 1 u may E R A Q E MB m mkq 7 Q m. k a gm HNMNNQQ ww u QNNS mum mmfi NJ EN 7 u E g msw g3 @Y 5% Ram .EQEEQ .NQNQLM Q g ww NEE y aw J m s. m N EN L v x m N N Patented Apr. 20, 1937 UNITED STATES RAILWAY TRAFFIC CONTROLLING APPARATUS Henry S. Young, Wilkinsburg, and Ronald A.

McCann, Swissvale,

Pa, assignors to The Union Switch & Signal Company, Swissvale, Pa, a corporation of Pennsylvania Application December 14, 1935, Serial No. 54,430

6 Claims.

Our invention relates to railway traflic controlling apparatus, and more particularly to apparatus involving the control of signals arranged between passing sidings of a single track stretch of railway.

An object of the invention is to provide means for preventing an operator from setting at stop the signals for governing traflic movements in a given direction through a single track stretch, if the operator should erroneously attempt to clear an opposing signal while the signals for the given direction are indicating caution or proceed. Another object of the invention is to provide means for preventing the automatic clearance of an intermediate signal governing traffic movements in a given direction, when an opposing signal at one end of the stretch has been cleared and is returned to stop as a'result of a train over-running a signal governing traffic movements in the given direction at the other end of the stretch.-

The apparatus of our invention is an improvement over that disclosed in the copending applications Serial No. 125,659 filed July 29, 1926, by H. A. Wallace, for Railway traific controlling apparatus; Serial No. 313,772 filed October 20, 1928, by H. A. Thompson, for Multiple control apparatus; Serial No. 379,163 filed July 18, 1929, by C. A. Brooks, for Multiple control apparatus; and Serial No. 505,328 filed Dec. 29, 1930, by E. M. Allen, C. A. Brooks and H. A. Thompson, for Railway trafl lc controlling apparatus.

We will describe two forms of apparatus embodying our invention, and will then point out the novel features thereof in claims.

In the accompanying drawings, Figs. 1 to 3, inclusive, when placed end to end from left to right in the order named, constitute a diagrammatic view showing one form of apparatus embodying our invention, while Figs. 1 and 3 show apparatus and circuits which may be used in conjunction with Figs. 1, 2 and 3 to illustrate an alternative form of the invention.

Similar reference characters refer to similar parts ineach of the views.

The invention, as illustrated, is applied to a stretch of single track railway X extending eastward from a passing siding P2, shown at the lefthand end of Fig. 1, to a passing siding P'I, shown at the right-hand 'end of Fig. 3.

v By means of insulated rail joints, designated by the reference character 3, the trafiic rails of the stretch, designated by the reference characters I and la, respectively, are divided into track sections IT to 8T, inclusive, with only the west end of section 8T and the east end of section IT shown. Sections 2T and IT include track switches 2 and l of the associated sidings P2 and P1, respectively. Each track section is provided with a track circuit, including a battery designated by the reference character 6 and a track relay designated by the reference character R. with a prefix designating the section to which it belongs.

The signals may be of any suitable type, but for the purposes of this disclosure color light signals have been used. The signals shown in Fig. 1, designated RAZ and RBZ, respectively, govern eastbound traffic movements over switch 2 inits normal and reverse positions, respectively; while the signals designated LA2 and LBZ govern westbound trafilc movements over switch 2 in its normal and reverse positions, respectively.

The reference characters R2I-IS and LZHS designate a pair of directional relays which may be controlled from a remote point in any satisfactory manner to control traihc movements over switch 2 when tramc conditions are favorable, as indicated by the energized condition of the home relays, herein designated RZH and L2H, respectively. The controlling circuits for relays RZI-IS and LZHS form no part of our present invention, but they may, for example, be controlled by manual operation of suitable circuit controllers at a remote point, such as a train dispatchers ofiice.

Relay R2HS controls a slow releasing signal control relay RAH-1P or RBZI-IP in the signal network, depending on the position of switch 2 indicated by the associated switch position repeating or indicating relay ZKR, to govern eastbound traffic movements over switch 2. In a similar manner, relay LEI-IS controls signal control relays LA2HP and LBZHP to govern westbound traffic movements over switch 2. e

In the accompanying drawings, the contacts of each relay are generally shown directly under their relay, but in each case where this is not done, the contact is connected with the relay by a dashed line or is'labeled with its relay designation and with a numerical sufiix.

The source of current employed has been diagrammatically illustrated in Fig. 2 as a battery having a center tap designated as terminal C, and positive and negative terminals designated B and N, respectively. It should be understood that while only one source of current has been illustrated, separate sources; such as the one shown for example, may be provided at the ends of the stretch and at the intermediate signal location, in which case the center tap of each source would be connected to a common line wire.

Referring again to Fig. 1, the reference characters RZMR and L2MR designate approach locking relays for eastbound and Westbound trafiic movements, respectively, over switch 2. It should be understood that, although notshown in the drawings, the switch machine for switch 2 is controlled by these approach locking relays in the usual manner, so that switch 2 can not be operated with either relay Rim or LZMR released. Approach locking relay RZMR is also herein employed to prevent the automatic clearance of an intermediate signal under dangerous traflic conditions, as will subsequently be explained.

Relay RiMR is normally held energized, both a pickup and a stick circuit for this relay being normally closed. The normally closed pickup circuit for relay R2MR passes from terminal B, through contacts Zl and 4i of relays RAZI-IP and RBZI-IP, respectively, neutral front contact 48 and normal polar contact 49 of relay ZKR, contact 45 of relay REAR, contact RZHSI, and the winding of relay RZMR to terminal C. The stick circuit passes from terminal B, through back contacts 2'! and ii of relays RA2HP and RBEHP, respectively, conductors Elia, Nib and 380, the front point of contact 28 of relay RZMR, and the winding of relay RZMR to terminal C.

Relay LZMR is similarly normally held energized. Its stick circuit passes from terminal B, through back contacts 58 and 59 of relays LA2HP and LBZHP, respectively, the front point of contact iii of relay LZMR, and the winding of relay LZMR to terminal 0. The pickup circuit for relay LZMR which is also normally closed is similar to the stick circuit except that it includes front contact 6d of an approach relay LEAR. instead of contact 6! of relay 112MB.

A second approach relay, designated RZAR, is also provided. Relay REAR is normally energized over a circuit including front contact ITRZ, while relay LZAR is normally energized over a circuit passing from terminal B, through front contacts 3! and 32 of track relays 5TB and 4TH, respectively, Wire LWS, the winding of relay LZAR, and front contact 3 of track relay 3TB to terminal C.

The reference character ETE designates a time element relay of a commonly employed type, provided with contacts 92 and 9A which are closed a predetermined time interval after the relay is energized, to govern the release of approach locking relays RZMR and LZMR, respectively, and also having a contact l5 included in the signal control circuit network.

Relay L2H is normally energized by a circuit which is controlled by contact ITRI. As indicated by the dash line between terminal B and contact lTRi, relay L2H may also be controlled by other means such, for example, as trafiic conditions for the stretch of track west of section IT.

Relay RZH is normally energized by current of normal polarity passing from terminal B, through the front point of contact SI-IPl, contacts 5H! and lSl, contact 55 of relay lTR, conductor LWI, contact ETRI, and the winding of relay RBI-I to terminal C.

As shown in Fig. 1, switch 2 is in its normal position. With switch 2 in its normal position, pole-changer 9, which is controlled by switch 2, is in its normal position, and relay ZKR is therefor energized by current of normal polarity. The front contacts of relay QKR are therefore closed, and its normal polar contacts are also closed.

Relays RAEHP and RBZI-IP are normally deenergized. Red lamp R of signal RA2 is therefore lighted by a circuit including the back point of contact 229 of relay RA2HP, and red lamp R of signal RBZ is lighted by a circuit including the back point of contact 69 of relay RBZHP.

In Fig. 2, the intermediate portion of track X is provided with intermediate signals A and 5 for governing the movement of westbound and eastbound traflic, respectively. These signals and associated directional stick relays designated 48 and 58, are controlled by the signal control relays which are designated H and HP, respectively, with a prefix corresponding to their associated signal. For example, signal 4 is controlled by relay 4H and by the slow pickup and slow release repeater relay ll-1P. Relay QH is normally energized by current of reverse polarity over a circuit passing from terminal N, through the back point of contact 2! of relay LAZI-D? in Fig. 1, front contacts 22 and 23 of track relays 3TB and 2TR, respectively, back contacts 25 and 25 of relays RBZI-IP and RAEHP, respectively, conductor J2, front contact RZMRl, wire LW3, front contact 26 of relay l'IR, and the winding of relay 41-1 to terminal C. Relay AHP is normally energized over a circuit including front contact 29 of relay 4H.

With relay 4H energized by current of reverse polarity and with relay QHP energized, lamp Y of signal 4 is lighted by a circuit passing from terminal B, through the front point of contact 38 of relay iHP, contact 39 of relay 41-1 in its reverse position, and lamp Y of signal 4 to terminal C.

Referring now to Fig. 3, the signals RAT, RBI, LA? and LB? are identical to the similarly located signals at the opposite end of the stretch of track X, and the apparatus and circuits of Fig, 3 control the signals therein in the same manner as the signals of Fig. 1 are controlled. The wires LW 2, LWd and LWE extending between Figs. 2 and 3 are included in circuits which are equivalent to those passing over wires LWI, LW3 and LW5, respectively.

In order to further describe the invention, it Will first be assumed that the circuits and apparatus are in their normal condition, as shown, and that an operator proceeds to clear signals RAZ and RA! for directing an eastbound train through the stretch, by picking up directional control relays RZHS and R'IHS, respectively.

When relay RZI-IS picks up, the front point of its contact i5 completes a circuit for relay RAZHP, passing from terminal B, through back contacts H, 12 and 13 of relays LAZHP, LBZHP and LZHS, respectively, (checking that the L2 signals are at stop), front contact I4 of track relay 2TH, back contact I 5 of relay 2TE, the front point of contact E6 of relay R2HS, front contact ll of relay RZI-I, the front neutral and normal polar contacts l8 and I9, respectively, of switch position repeating relay ZKR, and the winding of relay RAZHP to terminal C. Relay RAZHP accordingly picks up and at the back point of its contact 2! opens the circuit for the R lamp of signal RAZ and at the front point of this contact, closes the circuit, including contacts 88 and ll] of relay R2H, for the G lamp of this signal, thereby changing the indication of signal RA2 from stop to proceed. Relay RAEHP also, at back contact 25, opens the circuit for relay 4H, and at back contact 27, opens the pickup and stick circuits previously traced for approach locking relay R2MR. When relay RZMR releases, its front contact RZMRI opens another point in the circuit for relay 5H, and contact 28 closes its back point in an operating circuit for time element opens the circuit for slow-acting relay 4HP, and

its front contact 4Hl opens the circuit for relay L7H passing from terminal B, through front contacts 4I-IPI and 4Hl, back contact 55! front contact 34 of track relay 5TB, wire LW2, front contact BTRI, and the winding of relay ,LIH to terminal C.

vWhen relay L1H releases, it opens at front contact 31, a common point in the operating circuits 10 for relays LA'IHP and LBlI-IP, thereby insuring that signals LA! and LB! will continue to display the stop indication irrespective of the condition of the operator controlled directional relay L'IHS.

When relay 4HP releases,,the front point of 1.; contact 38 opens the circuit for the Y lamp of signal 4, and the back point of this contact closes the circuit for the R lamp of this signal, so that the indication of signal 4 changes from caution to stop. Relay 4I-IP also, at the front point of contact dHPl, disconnects the operating circuit for relay L1H from terminal B, and connects this circuit to terminal N at the back point of the same contact.

When relay R'lHS is picked up to clear the leaving signal RA! for the trafiic movement under consideration, it opens another point in the operating circuits for relays LA'IHP and LB'IHP at the back point of contact 4!. Relay R'IHS, at the front point of contact M, completes a circuit for relay RA'IHP or RBlI-IP, depending on the position of switch 1 through its switch position repeating relay 'IKR. With switch 1 and relay 'IKR in their normal position, as shown, the circuit includes relay RA'IHP, and is similar to that for relay RAZHP at the other end of the stretch. When relay RAIHP picks up, the indication of signal RA! is changed from step to proceed in the same manner as the indication of signal RA2 was changed when relay RAZHP picked up.

40 Relay RATHP also, at the back point of contact 42, disconnects terminal N from the circuit for relay 5H, which is similar to the circuit previously traced for relay 4H, and, at the front point of this contact, connects terminal B to the same circuit. Relay 5H accordingly moves its polar contact 43 from the reverse position, in which it is shown, to the normal position, thereby opening the circuit for the Y lamp of signal 5, which is similar to the circuit traced for the corresponding lamp of signal 4, and closing the circuit for the G lamp thereof, so that the indication of signal 5 changes from caution to proceed.

Relay RA'JHP also, at back contact 1'6, opens a common point in the pickup and stick circuits for relay R'FMR, which are similar to the circuits previously traced for relay LZMR, and relay R'IMR accordingly releases to prevent movement of switch I while an associated signal is displaying a proceed indication.

If now a train enters section 2T, track relay 2TB, releases and, at front contact it, opens the circuit for relay RAZHP, sothat this relay will release and thus cause the extinguishing of the G lamp and the lighting of the R lamp of signal HA2, thereby changing the indication of signal RA2 from proceed to stop while section 2T is occupied, irrespective of the condition of relay RZHS. Track relay 2TB, in releasing, also opens a point in the circuit for relay H1 at front contact 23, to prevent the closure of this circuit when relay RZMR picks up.

Relay 2TB. also closes a pickup circuit for relay RZMR, providing the operator has released relay RJHS following the entry of the train into section IT, This circuit passes from terminal B,

through back contacts 2'! and 41 of relays RAZI-IP and RBZHP, respectively, conductor 30a, contacts 35 and RZHSI of relays 2TB and RZHS, respectively, and the Winding of relay RZMR to terminal C.

It may be observed at this time that front contacts 23, 22 and 26 of relays 2TB, 3TB and 4TH, respectively, of sections ZT- IT are included in the circuit for relay 4H, and therefore relay 4H will be unable to pick up and effect clearance of signal 4 until after the train has vacated all of these sections.

When the train enters section 3T, relay 3TB. releases, and opens the circuit for approach relay LZAR at front contact 8. Relay LZAR then re leases and, at its front contact 60, opens the pickup circuit previously traced for relay LZMR, without effect however at this time as the stick circuit for relay LZMR has not been interrupted.

When the train enters section 4T, relay 4TB. releases, and opens a further point in the circuit for relay L2AR at front contact 32, and also opens the circuit for approach relay RIAR at front contact 62. Relay RIAR accordingly releases and, at its front contact 66, opens another point in a pickup circuit for relay R'IMR.

When the train enters section 5T, relay 5TH releases and, at. its several contacts, makes circuit changes corresponding to those made upon the release of relay lTR. Relay 5H, however, which has been energized up to this time, now releases, and opens a further point in the circuit for relay RiH at front contact 5Hl, and opens the circuit for its slow-acting repeating relay SHP at front contact 86.

Before relay 51-? releases, however, a pickup circuit is completed for stick relay 53, passing from terminal B, through back contact 66 of relay 5TR, the front point of contact 6'! of relay EHP, and the Winding of relay ES to terminal C. Stick relay 5S now picks up and opens a further point in the circuit for relay L1H at back contact 58!; at front contact 5S2, closes a path around front contact 5I-Il, so that a circuit for relay R2H can be completed as soon as the train vacates section 4T; and closes front contact 68 in its own stick circuit.

An instant later, relay 5H1 releases, and opens the pickup circuit for relay 58 at the front point of contact 61, and, at the back point of this con tact, completes the stick circuit for relay 58, passing from terminal B, through the back point of contact 51, contact 68 of relay 5S, and the winding of relay 58 to terminal C. Relay 5HP also disconnects terminal B from the circuit for relay R2H at the front point of contact 5HP| and, at the back point of this contact, connects this circuit to terminal N.

When the train vacates section 4T, and relay 4TB picks up, a circuit for relay RZH including contact 582 and the back point of contact EHPI, is established by the closure of front contact 55 of relay dTR, but since the direction of current flow has been reversed at contact 5HPI, the polar contacts it! and H of relay RZH move to their reverse position. If relay RZHS is closed, the circuit for relay RAZHP will now again be established by the closure of front contact I! of relay RZH, and the circuit for the R lamp of signal HA2 will accordingly be opened, and that of the Y lamp thereof closed through contact 10 of relay RZH in its reverse position, so the indication of signal RAZ will change from stop to caution.

As the train advances into section 6T, track relay BTR releases, and opens a further point in the circuit for relay L1H at front contact GTRI. Relay BTR also opens a further point in the circuit for relay 5H at front contact 74; and maintains the circuit for relay R'IAR open at front contact 15, so that neither of the relays 5H and R'IAR will be able to pick up until after the train vacates section 6T.

When the train enters section IT, relay 'ITR releases, and opens the circuit for relay RA'IHP at front contact 77. Relay TTR also opens a point in the circuit for relay 'ETE at front contact 18 to prevent a circuit being completed for relay TE upon the closure of back contact 16 of relay RAVI-1P an instant later. Relay 'lTR also prepares a pickup circuit for relay RTMR at back contact 82 by closing a path around front contact 64 of relay R'IAR.

An instant after relay 'ITR releases, relay RA'IHP releases, and opens the circuit for the G lamp of signal RAi, and completes the circuit for the R lamp of this signal, so that its indication changes from proceed to stop.

Relay RAlHP also completes the pickup circuit prepared for relay R'lMR, by the closure of back contact 76. This pickup circuit passes from terminal B, through contacts 8| and 76 of relays RBIHP and RA'FHP, respectively, contact 82 of relay 'lTR, and winding of relay RTMR to terminal C.

When relay RiMR picks up, the back point of its contact 98 opens another point in the circuit for relay ITE, to prevent the energization of relay TE upon closure of front contact 18 of relay 'ITR as the train vacates section 1T. Relay R'IMR also re-establishes its own stick circuit at the front point of contact 98.

When the train vacates section 6T, relay BTR picks up and recloses the circuit for relay RTAR at front contact 75. Relay R'IAR accordingly picks up, and recloses the initial pickup circuit for relay R'IMR at front contact 64 which circuit passes from terminal B, through back contacts 8! and 16 of relays RB'lI-IP and RA'IHP, respectively, front contact 64 of relay R'lAR, and the winding of relay RJMR. to terminal C.

When the train enters section 8T, relay BTR releases, and opens the pickup circuit for relay L'IAR at front contact 8TR2. Relay LlAR in turn releases and, at front contact 93, opens the normally closed pickup circuit for relay LiMR, but without effect at this time as the stick circuit for relay LTMR has not been opened.

As the train vacates section 7T, relay 7TB again picks up, and recloses the circuit for relay 5H at front contact 84. Relay 5H then picks up, and in turn closes the circuit for relay 5HP. When relay 5HP picks up, it opens the circuit for stick relay 58 at the back point of contact 61, and relay 5S accordingly releases.

After the train vacates section 8T, track relay 8TR again picks up, and recloses the control circuit for relay LEAR which, in turn, recloses the normally closed pick-up circuit for relay L'IMR.

If, after signal RA? or RB2 and signal RA! or RB! have been cleared, the operator erroneously picks up relay L'IHS, relay RAIHP will be deenergized by the opening of contact 95 of relay LlHS at its back point, causing signal RAT to now indicate stop and causing signal 5 to indicate caution, and the storage of the clearance of one of the opposing signals LAT or LB? will also result, depending on the position of switch I. Signal RA2 will continue to indicate proceed. When relay L'IHS picks up, the front point of its contact 95 cannot complete a circuit for either of the signal control relays LA'IHP or LBlI-IP, since their operating circuits are open at the back point of contact 4| of relay R'lI-IS, and also at front contact 31 of relay L1H if the eastbound train has not passed beyond section 6T. It will be observed that the opening of back contact LIHSI is without effect at this time, as the stick circuit for relay LIMR has not been opened. Since relay L'IMR is not released, its front contact L'IMRI, in the circuit for relay 5H, is not opened at this time.

When the train vacates section IT, relay 'ITR again picks up and, at its front contact 84, closes the circuit for relay 5H, irrespective of the condition of relay L'IHS. Relay 5H accordingly picks up and, by picking up relay EHP, effects the release of stick relay 5S. The latter relay, on releasing, closes its back contact 5Sl in the circuit for relay L1H, which accordingly picks up and enables signal LA! to be cleared if the operator has deenergized relays R2I-IS and R'IHS.

If, after signal RA2 or RB2 and signal RAT or RB! have been cleared, a train moving toward the left over-runs signal LAI or LB! at stop, relay lTR releases and opens the circuit for relay SE at its front contact 84, thereby causing the release of relays 5H and 5HP at the intermediate signal location, and of relays RZI-I and RAH-1P or RBZHP at the west end of the stretch. The indication of signal RAZ or RBZ and of signal 5 accordingly changes from proceed to stop. Signal t will also continue to display its stop indication, on account of relay RZMR being deenergized.

With relays REMR, RAZHP and RBZHP released, a circuit for time element relay ZTE is completed, passing from terminal B, through back contacts 21 and 41 of relays RA2HP and RBZHP, respectively, conductors 30a, 30b and 300, back point of contact 28 of relay RZMR, front contact 5? of relay ZTR, and the winding of relay ZTE to terminal C.

The operator can now energize relay 4H by releasing relay RZHS. With relay RZHS released and approach section IT unoccupied, relay RZMR immediately picks up over the pickup circuit first traced for this relay, through contact 45 of relay RZAR. If, however, section IT is occupied, relay RZMR will not pick up until relay ZTE closes its contact 92 and thereby completes a third pickup circuit for relay RZMR, passing from terminal B, through contacts 21 and 4'! of relays RA2HP and RBZHP, respectively, conductors 30a and 30b, contact 92 of relay 2TE, contact R2HSI, and the winding of relay RZMR to terminal C.

Relay REMR, upon picking up, opens the circuit for relay ZTE at the back point of contact 28, and again completes the circuit for relay 4H at its front contact RZMRI. Relay 4H accordingly picks up to effect a change in indication of signal 4 from stop to proceed or from stop to caution according as relay LAZHP is energized or de-: energized.

The alternative form of our invention involves the use of an HS repeating relay at each end of the stretch. These relays and their energizing circuits are illustrated in Figs. 1a and 3a, and are designated R2HSP and LIHSP, respectively. Accompanying changes in the circuits comprise the use of conductors J I and J3, shown by dash lines, instead of contacts RZHSI and LlHSI of relays RZHS and LIHS, respectively, in the circuits for relays RZMR and L'IMR, and the use of contacts R2I-ISPI and LTI-ISPI, also shown by dash lines, instead of conductors J2 and J4, respectively.

In this form of the invention, when relay RZHS is picked up, its front contact RZHSZ closes a circuit for relay RZI-ISP, only if front contact RZHI is closed. Back contact R2HSP| functions in a similar capacity to that of back contact RZHSI in the first described form of the invention, in that it prevents signal 4 from being cleared until after relay RZHS has been released.

To explain the operation more fully, it will be assumed that signals RA2 and RA! have been cleared and that the operator inadvertently picks up relay L'IHS. When relay LII-IS is picked up, its front contact LIHSZ closes, but since front contact L'lHl is open, relay L'lI-ISP cannot pick up and therefore cannot open its contact L'IHSPI to open the circuit for relay 5H. Hence, although signal RA! will now indicate stop, signal 5 will indicate caution, and signal RAZ will continue to indicate proceed.

If signal RA2 is cleared for an eastbound traffic movement, and if a westbound train over-runs signal LA! at stop, track relay 'FTR will release and cause the indication of signal HA2 and of signal 5 to change from proceed or caution to stop in the manner already described. In this form of the invention, since the pickup circuit for relay R2MR does not include a back contact of relay RZHS, relay RZMR will pick up at once if approach section IT is unoccupied, or alternatively as soon as time element relay ZTE has fully operated, if section IT is at the time occupied. I-Io-wever, before signal 4 can be cleared, back contact R2HSP| must be closed. The operator must therefore release relay RZI-IS, and break the stick circuit for relay RZHSP at contact R2HS2 to effeet the release of relay RZI-ISP, in order to clear signal 4.

Since the circuits and apparatus for directing westbound trafiic movements over the stretch, ir-

respective of the form of the invention employed,

are identical to those already described, their control and operation will be fully understood Without further explanation.

Although we have herein shown and described only two forms of apparatus embodying our invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without depiarting from the spirit and scope of our inven- Having thus described our invention, what we claim is:

1. In a railway signaling system, a stretch of single track railway having a passing siding and an associated switch at one end thereof, signals for governing the movement of traffic into the stretch over said switch in its normal and reverse positions respectively, control relays for said signals, an approach locking relay 'for said switch, a remotely controlled directional relay having a front contact included in a circuit including one or the other of said control relays according as the switch is in its normal or its reverse position, an opposing signal for governing traffic movements toward the siding and controlled by a line relay with an energizing circuit including a front contact of said approach locking relay, a pickup circuit for said approach locking relay including back contacts of said remotely controlled and said control relays respectively, and a stick circuit for said approach locking relay similar to said pickup circuit but not including the back contact of said remotely controlled relay.

2. In a railway signaling system, a stretch of single track having a passing siding and an associated switch at one end thereof, signals for go-v- T posing signal for governing trafiic movements toward the siding and controlled by a line relay with an energizing circuit including a back contact of said repeating relay, a pickup circuit for said repeating relay including front contacts of the first specified line relay and of the remotely controlled relay respectively, and a stick circuit for said repeating relay including a front contact of said remotely controlled relay.

3. In combination, a stretch of single track railway, a first and a second as well as a third and a fourth signal spaced along said stretch in the order named with the first and second and third signals governing trafiic movements in a given direction over said stretch and the fourth signal governing trafiic movements in the opposite direction over said stretch, a first and a second and a third manually operable device, a circuit controlled by said first and third manually operable devices for controlling said first signal to display a more favorable indication than stop if said first manually operable device is operated while said third manually operable device is in its normal condition, a second circuit by which said second signal is normally maintained in condition to display a more favorable indication than stop, a third circuit controlled by said second and third manually operable devices for controlling said third signal todisplay a more favorable indication than stop if said second manually operable device is operated while said third manually operable device is in its normal condition, a fourth circuit controlled by said first and second and third manually operable devices for controlling said second signal to indicate stop and said fourth signal to display a more favorable indication than stop if said third manually operable device is operated while said first and second manually operable devices are in their normal condition, and means controlled by said first manually operable device when in condition to control said first signal to display a more favorable indication than stop for preventing operation of said third manually operable device from changing the indication of said second signal to stop.

4. In combination, a stretch of single track railway, a signal adjacent a given end of said stretch for governing traffic movements in a given direction into said stretch, a second signal adjacent the second end of said stretch for governing traffic movements in an opposite direction into said stretch, a third and a fourth signal located between the ends of said stretch for governing trafiic movements in said given direction and the opposite direction respectively, a manually controlled relay for said first signal, a second manually controlled relay for said second signal, an approach locking relay associated with said first signal, a second approach locking relay associ- 'ated with said second signal, a control circuit for said third signal including a front contact of said second approach locking relay and closed only if the track is unoccupied between said second and third signals, a control relay for said first signal, an energizing circuit for said control relay controlled by trafiic conditions between said first and third signals and closed only if the control circuit for said third signal is closed,

10 a control circuit for said fourth signal including a front contact of said first approach locking relay and closed only under favorable trafiic conditions between said first and fourth signals, a second control relay for said second signal, an

energizing circuit for said second control relay controlled by trafiic conditions between said second and fourth signals and closed only if the control circuit for said fourth signal is closed, a pick-up and a stick circuit for said first approach locking relay one of which is closed through a back contact of said first manually controlled relay and the other of which is closed only while said first signal is controlled to indicate stop, a pick-up and a stick circuit for said 5 second approach locking relay one of which is closed through a back contact of said second manually controlled relay and the other of which is closed only while said second signal is controlled to indicate stop, a circuit controlled by a front contact of said first manually controlled relay and by a front contact of the first control relay for controlling said first signal to display a more favorable indication than stop, and a circuit controlled by a front contact of said second manually controlled relay and by a front contact of said second control relay for controlling said second signal to, display a more favorable indication than stop.

5. In combination, a stretch of railway track,

a signal for governing traffic movements in a given direction over said stretch, a second signal for governing traffic movements in the opposite direction over said stretch, a manually controlled relay, a control relay for said first signal controlled by track circuit conditions in said stretch, an approach locking relay associated with said first signal, a pick-up and stick circuit for said approach locking relay one of which is controlled by traffic conditions in said stretch and the other of which is closed only while said first signal is controlled to indicate stop, means controlled by a front contact of said, manually controlled relay and by a front contact of said control relay for controlling said first signal to display a more favorable indication than stop, a stick relay, a pick-up and a stick circuit for said stick relay one of which is controlled by a front contact of said control relay and by a front contact of said manually controlled relay and the other of which is controlled by a front contact of said manually controlled relay, and a circuit controlled by a back contact of said stick relay and by a front contact of said approach locking relay for controlling said second signal to display a more favorable indication than stop.

6. In combination, a stretch of railway track, a signal for governing traific movements in a given direction over said stretch, a second signal for governing traffic movements in the opposite direction over said stretch, a manually controlled relay, a control relay for said first signal controlled by track circuit conditions in said stretch, means controlled by a front contact of said manually controlled relay and by a front contact of said control relay for controlling said first signal to display a more favorable indication than stop, a stick relay, a pick-up: and a stick circuit for said stick relay one of which is controlled by a front contact of said control relay and by a front contact of said manually controlled relay and the other of which is controlled by a front contact of said manually controlled relay, and a circuit controlled by a back contact of said stick relay for controlling said second signal to display a more favorable indication than stop.

HENRY S. YOUNG. RONALD A. MCCANN. 

